Efecto de la melatonina y L-carnitina en criosupervivencia y fertilidad de espermatozoides del gallo criollo (Gallus gallus domesticus)

Abstract

The mighty antioxidant action of melatonin (ME) and the locomotion-stimulating effect of L- carnitine (LC) have allowed to improve sperm cryosurvival of avian sperm. In this sense, this

research evaluated the effects of ME, and LC supplemented to the freezing medium on the cryosurvival and fertility of Creole roosters (Gallus gallus domesticus) spermatozoa. For this purpose, sixty ejaculated from 10 adult Creole roosters (8-24 months) collected by dorsal massage (in six sessions) were used to conform 12 pools. Each pool was divided into three aliquots, each diluted with Lake-Ravie extender and supplemented with 10 μM ME, 5 mM LC, and no antioxidants (as control). Semen samples were loaded into 0.25 mL straws, sealed and frozen with static liquid nitrogen vapors. A total of 360 straws were frozen: ME (n=120 straws), LC (n=120 straws) and control (n=120 straws). Half of the straws were thawed and analyzed for kinematics parameters and plasma membrane integrity using the CASA system and the propidium iodide fluorescent test, respectively. The other half of the straws were used to assess fertility after artificial insemination of 30 hens (10 hens per treatment) in 6 sessions. The results demonstrated that supplementation with ME and LC to the freezing medium improved sperm cryosurvival. Effectively, L-carnitine produced both locomotion-stimulating and cryoprotective effects by

increasing progressive sperm motility, plasma membrane integrity, and fertility after the frozen- thaw process. Nevertheless, melatonin only improved plasma membrane integrity or viability after

cryopreservation.